(build) Enable reproducible builds in build.gradle

Settings for enabling reproducible builds for all subprojects were added to improve build consistency. This includes preserving file timestamps and ordering files reproducibly.

This is primarily of help for docker, since it uses hashes to determine if a file or image layer has changed.

build.gradle

@@ -11,8 +11,8 @@ version 'SNAPSHOT'
 compileJava.options.encoding = "UTF-8"
 compileTestJava.options.encoding = "UTF-8"
 
-// Enable preview features for the entire project
 subprojects.forEach {it ->
+    // Enable preview features for the entire project
     it.tasks.withType(JavaCompile).configureEach {
         options.compilerArgs += ['--enable-preview']
     }
@@ -22,6 +22,12 @@ subprojects.forEach {it ->
     it.tasks.withType(Test).configureEach {
         jvmArgs += ['--enable-preview']
     }
+
+    // Enable reproducible builds for the entire project
+    it.tasks.withType(AbstractArchiveTask).configureEach {
+        preserveFileTimestamps = false
+        reproducibleFileOrder = true
+    }
 }
 
 allprojects {